I've had a pain in my left shoulder. low above my breast but below my collar bone. all day, for no apparent reason. now its pulling in my neck?

Emergency: Between your breast and collarbone is your chest. Pain there that radiates into your neck in a 53 year old definitely justifies a trip to the emergency department tonight to exclude serious causes like heart and lung problems.

ER: I would need to know a little bit more about your pain but it does concern me for a cardiac source. Women present differently than males. If its associated with any nausea, diaphoresis or radiation of the pain than you should be more concerned.

Pain: Pain in that area could be due to radiation from a shoulder tendonitis or be due to inflammation or strain of a pectoral muscle from some activity or exercise. Cold or hot packs and NSAIDS like ibuprofen may help. See your Physician if symptoms persist or worsen.

Pain.: It appears to be a pulled muscle. However, since I cannot examine you, I feel that you should see a doctor as soon as possible.